Genetic analyses of new movement traits using detailed evaluations of warmblood foals and mares.

The research focuses on a study where detailed movement evaluations of warmblood foals and mares were done in relation to breeding events. The findings gave insight into characteristics that indicate irregular movement patterns and imbalance, providing useful information for horse breeding.

About the Study

• The research carried out detailed movement evaluations of warmblood foals and mares during Oldenburg horse breeding events in 2009 and 2010.
• A special judge (SJ) and the regular judges (RJ) of the breeding events observed these horses for unfavorable movement characteristics indicative of an impaired balance.
• These observations played a crucial role in defining new movement traits and served as the basis for the study.

Findings and Observations

• The research found that severe irregular movements, like imbalanced hind legs or overall irregular movement patterns, were quite rare, with a prevalence of 1-2%.
• Around 4% of the foals and 5% of the mares showed irregular tail tone or posture.
• This led the researchers to calculate a prevalence of 6.2% (for foals) and 5.5% (for mares) for the broader trait indications of imbalance (IMB).
• All traits were coded in binary, and genetic parameters were estimated bivariately in linear animal models with residual maximum likelihood.

Comparison and Analysis

• The researchers compared the evaluations and definitions of traits by the special judge and regular judges.
• The differences between the trait definitions of SJ and RJ were more significant in the mares than in the foals. However, it was deemed appropriate to combine the information provided by both judge types in both age groups.
• The heritability estimates for the movement traits ranged from 0.02 to 0.26 in the foals and from 0.03 to 0.12 in the mares with heritabilities for IMB on the underlying liability scale of 0.46 (foals) and 0.22 (mares).

Implications and Conclusion

• The research suggested that common genetic factors could influence the findings of impaired balance in both foals and mares.
• The results implied that horse breeding could benefit from early information on the movement of foals obtained by detailed movement evaluations.
• For future genetic evaluations to be more beneficial, there may be a need for refined recording of unfavorable movement characteristics in adult horses.